Endoscopic imaging system making it possible to detachably attach expansion unit having external expansion facility and add expansion facility for improving capability of system

ABSTRACT

In an endoscopic imagining system, a signal representing an object image produced by a scope and projected by a camera head is processed by a CCU and displayed as an endoscopic image on a TV monitor. The object image is stored as digital image data on a memory in the CCU, read as image data of a still image, and recorded on a PC card mounted in a PC card slot. The PC card slot is formed in the front panel or the like of the CCU. A lid member or the like functioning as an anti-liquid invasion member and shield can be located at an opening of the slot.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an endoscopic imaging system in which aview image produced by an endoscope is projected.

2. Description of the Related Art

Endoscopes having elongated insertion units thereof inserted into bodycavities or the like and thus assisting in observation of objectregions, various kinds of examinations, and cures and treatments havebeen widely adopted in the past. Assume that an optical endoscope suchas a rigid scope or fiberscope is employed. In this case, generally, acamera head included in an endoscopic imaging system is attached to aneyepiece unit of the endoscope, and an endoscopic image is projected andviewed on a monitor or recorded for future diagnosis. Moreover, varioustypes of endoscopic imaging systems including an electronic endoscopethat is provided with an imaging device such as a CCD have been put touse.

An endoscopic image projected an endoscopic imaging system may berecorded for use in a clinical record or thesis. In this case,generally, the image has been filmed as a photograph in the past.Alternatively, the image has been recorded as a motion picture onvideotape by means of a VTR, or recorded as digital image data on aninformation-recording device such as a hard disk. Recently, a PC cardhaving a memory incorporated as a card-shaped compact portable recordingmedium therein has called people's attention.

A conventional endoscopic imaging system has not been designed so that afreely-detachable compact portable recording medium such as a PC card orany other expansion unit that has an external expansion facility can bedetachably attached to a main processor unit such as a camera controlunit. If a medium can be mounted directly in the main processor unit, itwould be quite convenient for reading image data on the PC card or thelike and help expand the capability of the system readily. However, asfar as the conventional system is concerned, an expansion slot in whichthe expansion unit is mounted must be included separately. This may leadto a complex system configuration and time-consuming handling and invitean increase in cost.

Moreover, a conventional endoscopic image to be recorded as a digitalsignal is compressed at a certain level of compressibility and thenwritten on a recording medium according to the JPEG or the like. Thisposes a problem of poor use efficiency of the recording medium.Otherwise, an endoscopic imaging system permitting manual change oflevels of compressibility is available. However, since a level ofcompressibility must be changed to another at every endoscopicexamination, there arises a problem that handling becomes a nuisance.Another problem is that this feature is unacceptable at a medical siteat which it is hard to touch the system.

Moreover, image quality such as a resolution requested for a medicalimage varies depending on an employed endoscope or solid-state imagingdevice, a medical field, or a lesion concerned. Image quality dealt withranges from high quality permitting a high resolution to low qualitysuffering from a low resolution. If a certain level of compressibilityis always used for compression, image data may be recorded at anunnecessarily low level of compressibility. This poses a problem thatthe use efficiency of a recording medium deteriorates.

Moreover, the situation of an object to be represented by an endoscopicimage varies depending on a field in which the endoscopic imaging systemis employed. For example, when a large-diameter laparoscope is employed,a picture size corresponds to a full size of a monitor screen. The toneof an object image is reddish as a whole. In the field of urology, asmall-diameter rigid scope is employed. The picture size corresponds tothe size of part of the monitor screen. The tone of an object image iswhitish.

For coping with the various use situations, a technology has beendisclosed in, for example, Japanese Unexamined Patent Publication No.7-194527. Herein, a ROM in which set data is stored is incorporated inan endoscope. A control unit reads the set data, and modifies a sequenceof controlling light adjustment or the like. However, a rigid scopeemployed in a surgical procedure and a camera head included in anendoscopic imaging system may be used in combination. A plurality oftypes of endoscopes may be attached to the camera head. There isdifficulty in storing the set data in the endoscopes. Even when thecamera head is provided with a ROM for storing the set data, it israther meaningless.

As mentioned above, a ROM in which set data is stored is incorporated inan endoscope, and a control unit references the set data to modifysetting for an operation such as light adjustment. Thus, theconventional system is adjusted to specifications for endoscopes thatare different from field to field, situations of objects, and otherdifferent use situations. However, an endoscope system may beconstructed by combining an optical endoscope such as a rigid scope anda camera head included in an endoscopic imaging system. In this case,there are problems that it is hard to store set data in the endoscope,and setting for an operation such as light adjustment cannot be modifiedaccording to a use situation.

Moreover, when the conventional endoscopic imaging system is employed, aproduced endoscopic image may be recorded on a compact portablerecording medium, which is freely attachable and detachable, such as aPC card. In this case, the recorded situation of image data on themedium is unclear to a user. This may result in such a drawback thatnecessary image data cannot be recorded or stored reliably, that is, animage cannot be recorded because of insufficient capacity, or previouslyrecorded image data is overwritten. Moreover, if the connected state ofa PC card is imperfect, recording of an image may fail.

OBJECTS AND SUMMARY OF THE INVENTION

An object of the present invention is to provide an endoscopic imagingsystem making it possible to detachably attach an expansion unit, whichhas an external expansion facility, to a main unit, and to readily addan expansion facility for improving the capability of the system.

Another object of the present invention is to provide an endoscopicimaging system making it possible to automatically compress anendoscopic imaga at an optimal level of compressibility, and to thusimprove the use efficiency of a recording medium.

Still another object of the present invention is to provide anendoscopic imaging system making it possible to readily achieve propersetting for an operation according to a use situation.

Yet another object of the present invention is to provide an endoscopicimaging system making it possible to readily check the recordedsituation of image data on a medium, and to thus prevent occurrence ofan error during image recording.

In an endoscopic imaging system according to the present invention, amain processor unit including a signal processing means for processing avideo signal representing an object image projected by an imaging meansis provided with an expansion slot to which an expansion unit having anexternal expansion facility is freely detachably connected. When anexpansion unit having an external expansion facility is detachablyattached to the main unit, the expansion facility can be added to thesystem readily. Thus, the capability of the system can be improved.

Other features and advantages of the present invention will be fullyapparent from the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 3 relate to the first embodiment of the present invention;

FIG. 1 is a block diagram showing an overall configuration of anendoscopic imaging system;

FIG. 2 is a front view showing a configuration of a front panel of acamera control unit shown in FIG. 1;

FIG. 3 is a diagram showing a variant of the camera control unit, whichis shown in FIG. 1, included in the endoscopic imaging system whosecapability can be expanded;

FIGS. 4 and 5 relate to the second embodiment;

FIG. 4 is a front view showing a structure of an expansion slot;

FIG. 5 is a sectional view of the expansion slot shown in FIG. 4;

FIGS. 6 and 7 relate to the third embodiment of the present invention;

FIG. 6 is a sectional view showing a structure of an expansion slot;

FIG. 7 is a sectional view showing a structure of a variant of theexpansion slot shown in FIG. 6;

FIGS. 8 to 16 relate to the fourth embodiment of the present invention;

FIG. 8 is a sectional view showing a structure of an expansion slot;

FIG. 9 is a sectional view showing a structure of an outer side of theexpansion slot shown in FIG. 8 and its surroundings with an expansionunit mounted in the expansion slot;

FIG. 10 is an oblique view showing component members to be assembledinto the expansion slot shown in FIG. 8;

FIG. 11 is an oblique view showing a structure of the expansion unitshown in FIG. 9 which is seen from the face thereof;

FIG. 12 is an oblique view showing the structure of the expansion unitshown in FIG. 9 which is seen from the back thereof;

FIG. 13 is an oblique view showing a structure of a variant of theexpansion unit shown in FIG. 11;

FIG. 14 is a sectional view showing a structure of a first variant ofthe expansion slot shown in FIG. 8;

FIG. 15 is a diagram showing a structure of a second variant of theexpansion slot shown in FIG. 8;

FIG. 16 is a diagram showing a structure of a third variant of theexpansion slot shown in FIG. 8;

FIGS. 17 to 20 relate to the fifth embodiment of the present invention;

FIG. 17 is a diagram showing a configuration of an endoscopic imagingsystem;

FIG. 18 is a diagram showing a configuration of an expansion unit shownin FIG. 17;

FIG. 19 is a flowchart describing the operation of the endoscopicimaging system shown in FIG. 17;

FIG. 20 is a diagram showing a configuration of a variant of theendoscopic imaging system shown in FIG. 17;

FIGS. 21 to 29 relate to the sixth embodiment of the present invention;

FIG. 21 is an oblique view showing the overall appearance of anendoscopic imaging system;

FIG. 22 is an explanatory diagram showing a system configurationpermitting connection of a plurality of types of endoscopes;

FIG. 23 is a block diagram showing a functional configuration of anendoscopic imaging system;

FIG. 24 is a front view showing a layout of components on the frontpanel of a camera control unit;

FIG. 25 is an explanatory diagram showing a situation in which an objectimage produced by a small-diameter scope is displayed;

FIG. 26 is an explanatory diagram showing a situation in which an objectimage produced by a large-diameter scope is displayed;

FIG. 27 is an explanatory diagram showing an example of set datarepresenting adjustment values associated with fields;

FIG. 28 is a flowchart describing an alarming operation to be carriedout when an incorrect memory card is inserted;

FIG. 29 is an explanatory diagram showing an example of an alarmdisplay;

FIGS. 30 and 31 relate to the seventh embodiment of the presentinvention;

FIG. 30 is an explanatory diagram showing a memory card dedicated to Dr.A out of a plurality of kinds of memory cards associated with doctors;

FIG. 31 is an explanatory diagram showing a memory card dedicated to Dr.B out of the plurality of kinds of memory cards associated with doctors;

FIGS. 32 to 36 relate to the eighth embodiment of the present invention;

FIG. 32 is a block diagram showing an overall configuration of anendoscopic imaging system;

FIG. 33 is a front view showing a layout of components on the frontpanel of a camera control unit;

FIG. 34 is a block diagram showing a configuration of an image recordingunit;

FIG. 35 is a block diagram showing a functional configuration of a JPEGcompression circuit;

FIG. 36 is an explanatory diagram showing a screen display on a monitor;

FIGS. 37 and 38 relate to the ninth embodiment of the present invention;

FIG. 37 is a block diagram showing an overall configuration of anendoscopic imaging system;

FIG. 38 is an explanatory diagram showing an information display on aliquid crystal display placed on the front panel of the camera controlunit;

FIGS. 39 and 40 relate to the tenth embodiment of the present invention;

FIG. 39 is a block diagram showing an overall configuration of anendoscopic imaging system;

FIG. 40 is an explanatory diagram showing a screen display on a monitor;

FIGS. 41 and 42 relate to the eleventh embodiment of the presentinvention;

FIG. 41 is a block diagram showing an overall configuration of anendoscopic imaging system;

FIG. 42 is an explanatory diagram showing a screen display on a monitor;

FIGS. 43 and 44 relate to the twelfth embodiment of the presentinvention;

FIG. 43 is a block diagram showing an overall configuration of anendoscopic imaging system;

FIG. 44 is a front view showing a layout of components on the frontpanel of a camera control unit;

FIG. 45 is an explanatory diagram for explaining a drawback of aconventional system that when liquid such as water is spilled over aCCU, the liquid invades into the interior of an expansion slot; and

FIG. 46 is an explanatory diagram showing a setting modification screenassociated with a doctor in the conventional system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

As shown in FIG. 1, an endoscopic imaging system 1 of this embodimentcomprises a camera head 2 having an imaging means incorporated therein,a scope 3 connected to the camera head 2, a light source apparatus 4 forsupplying illumination light to the scope 3, a camera control unit(hereinafter a CCU) serving as a main processor unit for processing asignal sent from the imaging means incorporated in the camera head 2,and a TV monitor 6 for displaying a standard video signal processed bythe CCU 5. The scope 3 is a rigid endoscope such as a laparoscope usedfor, for example, a surgical procedure in the field of surgery.

When the endoscope imaging system 1 is in use, a light guide 8 of thescope 3 is, as shown in FIG. 1, linked to the light source apparatus 4.Illumination light emanating from a lamp in the light source apparatus 4passes through a diaphragm that is not shown, is converged by a lens,and falls on the opposed end surface of the light guide 8. Theillumination light is transmitted to the scope 3 over the light guide 8,passes through the scope 3, and is emitted forward through the distalend of the scope 3. Thus, an object in a patient's body cavity or thelike is illuminated. An image represented by light reflected from theilluminated object is formed by the scope 3. A resultant object image isprojected by the imaging means in the camera head 2 through the scope 3.

A CCD 7 serving as the imaging means is located on the focal plane of animaging lens in the camera head 2. The object image is formed on theimage plane of the CCD 7, and photoelectrically converted. The CCD 7 isconnected to the CCU 5 over a camera cable 9 having a CCD driving signaltransmission line and CCD output signal transmission line insertedtherein. An output signal of the CCD 7 is sent to the CCU 5, andsubjected to various kinds of signal processing. A video signal outputfrom the CCU 5 is sent to the TV monitor 6. A view image of the objectis then displayed on the TV monitor 6.

The CCU 5 is provided with a CCD driver 10. The CCD driver 10 supplies aCCD driving signal to the CCD 7 over the CCD driving signal transmissionline in the camera cable 9, and reads a signal charge accumulated in theCCD 7. Moreover, the CCU 5 is provided with a preamplifier 11 andpre-processing circuit 12. A CCD output signal read by the CCD 7 istransmitted to the CCU 5 over the CCD output signal transmission line inthe camera cable 9. After the CCD output signal is amplified by thepreamplifier 11 in the CCU 5 in order to compensate for a loss occurringon the cable, it is input to the pre-processing circuit 12.

On the succeeding stage of the pre-processing circuit 12, there are anA/D converter 13 and Y/C separation circuit 14. The CCD output signalinput to the pre-processing circuit 12 is pre-processed by carrying outcorrelation double sampling (CDS) and sample-and-hold (S/H). Theresultant CCD output signal is input to the A/D converter 13 andconverted into a digital signal, and then input to the Y/C separationcircuit 14.

On the succeeding stage of the Y/C separation circuit 14, there are anRGB matrix circuit 15 and a white balance/black balance adjustmentcircuit 16. The digital signal input to the Y/C separation circuit 14 isrecomposed according to the line-sequential system. Three digitalsignals Y, CR, and CB propagating through different channels andconstituting the digital signal are then separated from one another,input to the RGB matrix circuit 15, and converted into an RGB digitalsignal. Thereafter, the white balance/black balance adjustment circuit16 adjusts the white balance and black balance of the RGB digitalsignal.

On the succeeding stage of the white balance/black balance adjustmentcircuit 16, there are a digital video processing circuit 17, a D/Aconverter 18, and a post-processing circuit 19. The RGB digital signalhaving undergone balance adjustment is digitally processed throughenhancement, gamma correction, and character convolution carried out bythe digital video processing circuit 17. Thereafter, the resultantsignal is converted into an analog signal by the D/A converter 18, andthen input to the post-processing circuit 19. The analog signal that isinput to the post-processing circuit 19 is converted into a standardvideo signal, and then output to the TV monitor 6.

Moreover, on the succeeding stage of the digital video processingcircuit 17, there are a memory 20, a JPEG compression circuit 21, and aPC card driver 22. A PC card slot 23 is connected to the PC card driver22. The digital signal having undergone various kinds of signalprocessing is stored in the memory 20. A PC card 24 having a memoryincorporated therein is mounted in the PC card slot 23. A digital imagesignal read from the memory 20 is compressed by the JPEG compressioncircuit 21, and then recorded on the PC card 24 via the PC card driver22.

Furthermore, the CCU 5 is provided with a CPU 25 responsible for variouskinds of control including control of image recording on the PC card 24,and a font generator 26 for outputting a display of medium informationincluding the number of image data items recordable on the PC card 24.Located on the front panel 28 of the CCU 5 are a release switch 29 usedto given a handling instruction (release instruction) for imagerecording and an LED 27 for displaying the medium information.

As shown in FIG. 2, a power switch 30, a connector receptor 31 intowhich the camera head 2 is plugged, the PC card slot 23, the LED 27, andoperation switches 32 including the release switch 29 are arranged onthe front panel 28 of the CCU 5. A compact memory card 33 such as asmart medium is detachably attached to the PC card 24.

In the endoscopic imaging system 1 having the foregoing components, animage signal produced by the scope 3 and visualized and processed by thecamera head 2 is output to the TV monitor 6 and displayed in the form ofan image. Besides, the image signal is stored in the memory 20.

When the release switch 29 is pressed for recording an endoscopic image,the CPU 25 sends a release signal to the memory 20. Image datarepresenting a still image is read from the memory 20. The read imagedata is compressed by the JPEG compression circuit 21. The image data isthen sent to the PC card 24 mounted in the PC card slot 23 via the PCcard driver 22, and then recorded.

Moreover, for image recording, medium information including thefrequency of releasing image data representing a still image, that is,the number of image data items recorded on the PC card 24 is sent fromthe CPU 20 to the font generator 26. The font generator 26 outputs theinformation as character information. The character information is thendisplayed in the LED 27 for displaying medium information on the frontpanel. The releasing frequency indicated with numerals in the LED 27 isincremented by one with every release.

When an endoscopic image is thus recorded using the PC card, recordingand storage of a still image whose quality has little deteriorated canbe realized easily at low cost. Thus, medium information including thenumber of image data items recorded on the PC card is displayed in theLED on the front panel of the CCU. This allows a user to readily checkthe number of remaining recordable images.

Moreover, the PC card slot may be formed in the front panel of the CCUso that the PC card can be detachably attached directly. This makes itpossible to expand the capability of the system with ease and goodhandling efficiency. Consequently, the capability of the system can beimproved.

FIG. 3 shows a variant of an endoscopic imaging system whose capabilitycan be expanded. In the CCU 5 of this variant, a PC card 35 to which aremote control unit 34 can be connected is detachably attached to the PCcard slot 23 in the front panel. The remote control unit 34 has a CPU,which controls remote control-related facilities on a centralized basisand is independent of the CPU in the CCU 5, incorporated therein. Whenthe remote control unit 34 is plugged into a remote control terminal 36of the PC card 35, the CCU 5 or the like can be handled and controlledusing the remote control unit 34.

In other words, the remote control unit is connected to the PC card slot23 instead of the PC card for recording image data as described inconjunction with the previous embodiment. Thus, control signals or thelike can be transferred via a digital input/output interface in theslot.

According to this configuration, a remote control facility desired by auser can be controlled without use of the CPU in the CCU. This obviatesthe necessity of including an interface dedicated to remote control inthe CCU. Consequently, the configuration of the system can be simplifiedand the cost thereof can be minimized.

An expansion unit to which the remote control unit is connected is notlimited to the PC card. The remote control unit may be connected to anyother expansion unit that can be detachable attached to the CCU.Otherwise, a CPU or the like may be incorporated in an expansion unititself so that the remote control facilities can be installed in theCPU.

In this embodiment, an expansion slot in which an expansion unit ismounted is formed in a main processor unit included in an endoscopicimaging system. The expansion unit intended for external expansion ofcapability, for example, a compact portable recording medium, which isfreely detachable and attachable, such as a PC card can be detachablyattached to the expansion slot. In this case, liquid may be split overthe main processor unit because of user's carelessness during anexamination or surgical procedure. The liquid may then invade into theexpansion slot. This would bring about a short circuit betweenelectrical contacts or corrosion in the main processor unit. A structurefor preventing invasion of liquid is therefore needed.

Second Embodiment

The conventional system does not have an anti-liquid invasion structureformed around an expansion slot. When liquid 38 such as water is splitover a CCU 37 as shown in FIG. 45, the liquid invades into the interiorof an expansion slot 39 in which an expansion unit 40 is mounted. Thismay invite a short circuit between electrical contacts or corrosion inthe CCU.

For improving the safety of medical equipment including a CCU with anexpansion slot, the expansion slot is provided with an anti-liquidinvasion means. An example of a structure including the anti-liquidinvasion means will be described as another embodiment.

FIGS. 4 and 5 show a structure of an expansion slot in accordance withthe second embodiment of the present invention. FIG. 4 is a front viewand FIG. 5 is a sectional view.

An eaves-like projection 42 is formed on the upper margin of the openingof an expansion slot 41 formed in the face or lateral side of a CCU 5over a range wider than the width of the opening. Liquid that has beensplit over the top of the CCU because of user's carelessness and flowingdown will be blocked by the projection 42 as indicated with an arrow 43.The liquid will not invade directly into the expansion slot 41.

According to the second embodiment, invasion of liquid into theexpansion slot can be prevented by a simple structure. Eventually, thefear of causing a short circuit between electrical contacts andcorrosion in the CCU can be eliminated.

Third Embodiment

In the third embodiment, as shown in FIG. 6, a slope 44 is formed aspart of an inner lower surface of an expansion slit 41 near the openingof the expansion slot. Owing to the slope 44, invasion of liquid intothe expansion slot can be prevented as indicated with an arrow 43.Moreover, in a variant shown in FIG. 7, the whole expansion slot 41 maybe formed on a slope 45. The same operation and advantage as thosementioned above can still be exerted.

According to the third embodiment, another member such as an eaves-likeprojection need not be formed. Besides, like the second embodiment,invasion of liquid into the expansion slot can be prevented despite thesimple structure.

Fourth Embodiment

The fourth embodiment is an example of a structure of an expansion slothaving an anti-liquid invasion means and a shield means for shieldingunnecessary radiative electromagnetic waves for attainingelectromagnetic compatibility (EMC).

A housing case 51 of a CCU is made of a conducting material, thusrealizing a shield structure against unnecessary electromagnetic wavesradiated from the interior of the CCU. As shown in the sectional view ofFIG. 8 and the diagram showing components to be assembled of FIG. 10,the housing case 51 has a case opening 53 bored for detachably attachingthe expansion unit 52 shown in FIG. 9. A unit mount 54 into which anexpansion unit 52 is fitted during mounting of the expansion unit isformed in the case opening 53. A contact connector 55 that iselectrically coupled with the expansion unit 52 when the expansion unitis mounted and that transfers an electrical signal or the like to orfrom the expansion unit 52 is formed at the deep end of the unit mount54.

A contact member 56 is sandwiched between the housing case 51 near thecase opening 53 and the unit mount 54 so that the contact member 56 willbe electrically coupled with the housing case 51. The portion of thecontact member 56 bordered by the upper side and lateral sides of thecase opening 53 is jutting to be a contact portion 56 a. A hinge member57 realized with a conductive member made of a metal or conductingrubber is located on the lower side of the case opening 53. One extremeportion of the hinge member 57 is fixed as a stationary portion 57 a sothat the portion will be electrically coupled with the housing case 51.The other extreme portion of the hinge member 57 can be opened or closedas a lid portion 58. The lid portion is constrained to move in adirection (direction of an arrow A in FIG. 8), in which it meets thecontact portion 56 a on the upper side of the case opening 53, by meansof a spring member 59 attached to the hinge member 57.

Furthermore, the portion of the inner lower surface of the unit mount 54inside the hinge member 57 is formed as a slope 60 opening on theoutside of the housing case 51.

The expansion unit 52 has, as shown in FIGS. 11 and 12, a conductor 61.The conductor 61 is realized with a conductive member coated over thecircumferential surfaces of a back portion of the expansion unit 52which comes back when the expansion unit is inserted into the expansionslot. When the expansion unit 52 is mounted in the expansion slot, asshown in FIG. 9, the contact portion 56 a of the contact member 56 overthe upper side and lateral sides of the case opening meets the conductor61 extending over the upper and lateral surfaces of the expansion unit52. An end of the lid portion 58 of the hinge member 57 meets theportion of the conductor 61 over the lower surface of the expansion unit52. This causes the lid portion 58 to conduct.

FIG. 13 shows a variant of the expansion unit 52. An expansion unit 62of the variant has a card slot 63 formed in a lateral surface thereof. Amemory card 64 such as a PC card can be mounted in the card slot. Likethe structure shown in FIG. 11, a conductor 61 is formed on the backportion of the expansion unit that comes back when the expansion unit isinserted.

When the expansion unit 52 is not mounted in the thus-formed expansionslot, the lid portion 58 of the hinge member 57 is constrained to movein the direction of an arrow A in FIG. 8 by means of the spring member59. This causes the lid portion 58 to meet the contact portion 56 a ofthe contact member 56 and thus conduct. The lid portion 58 is positionedto block the case opening 53. Thus, the lid portion 58 of the hingemember 57 fills the role of a lid for covering the case opening 53.Liquid flowing in from, for example, the top of the housing case 51 willflow along an arrow B in FIG. 8 but will not invade directly into theinterior of the unit mount 54. Moreover, liquid invading into theinterior of the housing case 51 through a chink in the hinge member 57can be prevented from invading into the interior of the unit mount 54owing to the slope 60 of the unit mount 54.

Moreover, when the expansion unit 52 is mounted, the conductor 61 on theexpansion unit 52, the contact portion 56 a of the contact member 56,and the end of the lid portion 58 of the hinge member 57 meet, as shownin FIG. 9, to conduct. This disables shielding, which is intended toattain EMC, of the case opening 53. Consequently, release of unnecessaryradiative noises can be prevented. At this time, since the case opening53 is blocked by the expansion unit 52, liquid can be prevented frominvading into the interior of the unit mount 54 in the same manner asthat when the expansion unit is not mounted.

FIG. 14 shows the first variant of the expansion slot of the fourthembodiment. The first variant has such a structure that a slope 65 isformed on a back portion of the expansion unit 52 that comes back whenthe expansion unit is inserted. Owing to the slope 65, even when theexpansion unit 52 is mounted, liquid flowing in from the top of thehousing case 51 flows in the direction of an arrow C in FIG. 13. Thisstructure can therefore prevent invasion of liquid into the interior ofthe unit mount 53 more reliably than the structure shown in FIG. 9.

FIG. 15 shows the second variant of the expansion slot of the fourthembodiment. The second variant has such a structure that bent parts 66are formed as parts of lateral ends of the lid portion 58 of the hingemember 57. Owing to the bent parts 66, the lateral sides of the caseopening 53 can meet the contact member 56 more reliably. This leads toimproved effects of preventing invasion of liquid and of shielding.

FIG. 16 shows the third variant of the expansion slot of the fourthembodiment. The third variant has such a structure that a lid member 67formed with a resin member and bent in the middle is substituted for thehinge member 57. A metallic film 68 is bonded to the surface of the lidmember 67. Owing to the lid member 67, a mechanical chink is not createdin a hinge 69. Consequently, an effect of preventing invasion of liquidcan be exerted more efficiently.

As mentioned above, according to the fourth embodiment, an expansionslot can be realized to have both an anti-liquid invasion structure forpreventing invasion of liquid into the expansion slot and a shieldstructure of achieving shielding for attaining EMC. This results inimproved safety of medical equipment including a CCU having theexpansion unit.

The adaptation of the endoscopic imaging system of this embodiment isnot limited to an endoscope system for surgery in which a camera head ismounted on a rigid endoscope as described in conjunction with theprevious embodiments. The endoscopic imaging system of this embodimentcan also be adapted to an endoscope system for internal medicine inwhich a camera head is mounted on a soft endoscope or an electronicendoscope having an imaging device incorporated therein.

Moreover, a PC card is not limited to a card having a memoryincorporated therein. A card to which a compact memory card such as asmart medium can be detachably attached, or a card having a compact harddisk incorporated therein can also be employed. Even when any expansionunit other than the PC card is mounted in an expansion slot, thestructure of the expansion slot can be adapted to the aforesaidembodiments.

Fifth Embodiment

(Configuration)

As shown in FIG. 17, an endoscopic imaging system 101 of this embodimentcomprises a TV camera-mounted endoscope 104 having a TV camera 103mounted on a rigid endoscope 102, a light source apparatus 105 forsupplying illumination light to the rigid endoscope 102, a cameracontrol unit (CCU) 107 for processing a signal sent from acharge-coupled device (CCD) that is a solid-state imaging deviceincorporated in the TV camera 103, a color monitor 108 for displaying anendoscopic image represented by a video signal output from the CCU 107,and an expansion unit 110 to be freely detachably plugged into a digitalvideo output terminal 109 formed in the CCU 107. As shown in FIG. 18, arecording medium can be connected to the expansion unit 110. Forexample, a PC card 112 serving as a recording medium can be freelydetachably connected to a PC card slot 111.

As shown in FIG. 17, the rigid endoscope 102 includes an elongatedinsertion unit 121, a hand-held unit 122 formed at the back end of theinsertion unit 121, and an eyepiece unit 123 formed at the back end ofthe hand-held unit 122. The hand-held unit 122 has a light guide base124, and is connected to the light source apparatus 105 over a lightguide cable 125.

Illumination light emanating from a lamp in the light source apparatus105 is converged by a condenser, and supplied to an incident end surfaceof a light guide in the light guide cable 125. The illumination light isemitted forward through the distal end surface of the light guide fittedin an illumination window located at the distal end of the insertionunit 121 over the light guide lying through the rigid endoscope 102.Thus, an object such as a lesion is illuminated.

Moreover, an objective lens is fitted in an observation window adjacentto the illumination window located at the distal end of the insertionunit 121. The objective lens forms an objective image at an imageformation position. The formed image is transmitted by a system of relaylenses that are arranged in the insertion unit 121 and opposed to theobjective lens. The image is then re-formed near the eyepiece unit 123.The image is then re-formed on the CCD 106 by an eyepiece lens includedin the eyepiece unit 123, and an image formation lens 126 included inthe TV camera 103 and opposed to the eyepiece lens.

Incidentally, a mosaic filter that is not shown is located in front ofthe image plane (photoelectric conversion plane) of the CCD 106. Colorcomponents of light incident on each pixel are optically separated fromone another. That is to say, an imaging means of this embodiment is asimultaneous imaging means for acquiring a color image signal underwhite illumination light.

The CCD 106 of the TV camera 103 is connected to the CCU 107. A CCDdriving signal is applied from a CCD driver 131 in the CCU 107 to theCCD 106, and photoelectrically converted into a CCD output signal (imagesignal). The CCD output signal is then input to an amplifier 132 in theCCU 107. The signal amplified by the amplifier 132 is input to apre-processing circuit 133.

The CCD output signal input to the pre-processing circuit 133 ispre-processed by performing correlation double sampling (CDS) andsample-and-hole (S/H). The resultant signal is then input to an A/Dconverter 134 and converted into a digital signal. The digital signal isinput to a digital signal processor (DSP) 135.

The DSP 135 recomposes the input digital signal according to theline-sequential system. Consequently, three digital signals Y, Cr, andCb propagating through different channels are separated from oneanother, and then converted into an RGB digital signal according to amatrix conversion formula. The RGB digital signal resulting from thematrix conversion has the white balance or black balance thereofadjusted. Thereafter, the resultant signal is digitally processed byperforming enhancement, gamma correction, and character convolution, andthen input to a D/A converter 136.

The digital signal input to the D/A converter 136 is converted into ananalog signal, converted into a standard video signal by apost-processing circuit 137, and then output to a color monitor 108.

Moreover, the CCU 107 is provided with a reference signal generator(SSG) 138. Based on a clock signal generated by the SSG 138, a timingsignal generator (TG) generates a timing signal. The CCD driver 131drives the CCD 106 in response to the timing signal. The clock signalsent from the SSG 138 is also output to the pre-processing circuit 133,A/D converter 134, DSP 135, and D/A converter 136. The CCD output signal(image signal) sent from the CCD driver 131 is processed synchronouslywith the clock signal.

Moreover, a digital video signal sent from the DSP 135 is output to adigital interface 141 under the control of the CPU 140. The digitalinterface 141 appends a control signal sent from the CPU 140 and adiscrimination signal that will be described later to the digital videosignal, and outputs a resultant signal to the expansion unit 110.Moreover, an enhancement switch 142 and a display panel 143 areconnected to the CPU 140. By handling the enhancement switch 142, amagnitude of enhancement to be achieved by the DSP 135 can be specified.

The discrimination signal to be appended to the digital video signal bythe digital interface 141 indicates the number of pixels and angularfield of view permitted by the CCD 106 in the TV camera 103, and a setvalue of the enhancement switch 142. The CPU 140 allows the DSP 135 toread these parameters and output them to the digital interface 141.Moreover, the parameters are displayed on the display panel 143.

As shown in FIG. 18, the expansion unit 110 includes a discriminationcircuit 151 for inputting an uncompressed digital video signal, to whicha discrimination signal is appended by the digital interface 141,extracting the discrimination signal, appending a compressibility signalproportional to the discrimination signal to the uncompressed digitalvideo signal, and outputting the resultant digital video signal. Theexpansion unit 110 further includes a compression circuit 152 forcompressing an uncompressed digital video signal, to which thecompressibility signal sent from the discrimination circuit is appended,at a level of compressibility indicated by the compressibility signal,and a recording unit 153 for recording the compressibility signal anddigital video signal on a PC card 112 via a PC card slot 111.

The PC card 112 is divided into segments associated with a plurality ofkinds, for example, patients or medical fields. Associated patient dataitems and medical-field data items are recorded in the segments. Thediscrimination circuit 151 can select a level of compressibilityaccording to patient data or medical-field data recorded on the PC card112, and provide a discrimination signal indicating the level ofcompressibility.

(Operation)

Next, the operation of the endoscopic imaging system 101 of thisembodiment having the foregoing components will be described.

For example, when the abdomen is operated under endoscopic observation,the TV camera 103 is mounted on the rigid endoscope 102 and connected tothe light source apparatus 105 and CCU 107. The color monitor 108 isconnected to the CCU 107. Moreover, the expansion unit 110 is pluggedinto the digital video output terminal 109 of the CCU 107. The PC card112 is connected to the PC card slot 111 of the expansion unit 110.

The insertion unit 121 of the rigid endoscope 102 is thrust into thepatient's abdomen by piercing the abdominal wall using a trocar andcannula. Thus, an organ in the abdomen can be observed. An (endoscopic)image of the organ is displayed on the color monitor 108. An operatorviews the image. When an image the operator wants to record is displayedon the color monitor 108, the operator handles a hand release switch orfoot switch that is not shown. Thus, an endoscopic image can be recordedon the PC card 112 in the same manner as photography. The recorded imagecan be utilized later by handling a personal computer or the like.

At this time, the CCD 106 of the TV camera 103 is driven synchronouslywith a clock signal sent from the SSG 138. The pre-processing circuit133, A/D converter 134, and DSP 135 process a digital video signalsynchronously with the clock signal.

The CPU 140 receives, as shown in FIG. 19, a signal sent from the DSP135 so as to read the number of pixels permitted by the CCD 106 as aparameter at step S11. At step S12, Table 1 is referenced in relation tothe read number of pixels, and then a discrimination signal is output tothe digital interface 141. The digital interface 141 appends thediscrimination signal to a digital video signal sent from the DSP 135.

TABLE 1 Parameter (Number of pixels) Discrimination signal 250 thousandpixels 01 h 410 thousand pixels 02 h 800 thousand pixels 03 h 3 CCD 04 h. . . . . .

Thereafter, at step S13, the discrimination circuit 151 in the expensionunit 110 reads the discrimination signal appended to the digital videosignal. The discrimination circuit 151 then references Table 2 inrelation to the discrimination signal, and appends a compressibilitysignal to the digital video signal. The resultant digital video signalis then output to the compression circuit 152.

TABLE 2 Discrimination signal Compressibility 01 h a 02 h b 03 h c 04 hd . . . . . .

Then, at step S14, the compression circuit 152 compresses the digitalvideo signal at a level of compressibility indicated by thecompressibility signal. At step S15, the recording unit 153 records theresultant digital video signal on the PC card 112 together with thecompressibility signal via the PC card slot 111. Thus, thecompressibility signal is recorded together with the compressed digitalvideo signal on the PC card 112. The compressed image can therefore bestretched properly by handling a personal computer or the like when itmust be stretched.

The parameter used at step S12 in FIG. 19 is not limited to the numberof pixels permitted by the CCD 106. Alternatively, the type of rigidendoscope 102 defined by an angular field of view permitted by the rigidendoscope will do. In this case, the CPU 140 uses as a parameter any ofa first endoscope, second endoscope, third endoscope, etc., which aresorted in that order from the smallest-diameter endoscope to thelargest-diameter one, to select a discrimination signal.

TABLE 3 Parameter (Angular field of view) Discrimination signal Firstendoscope 01 h Second endoscope 02 h Third endoscope 03 h Fourthendoscope 04 h . . . . . .

Moreover, the parameter used at step S12 in FIG. 19 may be a set valueof the enhancement switch 142. Based on the set value, Table 4 may bereferenced for selection.

TABLE 4 Parameter (Enhancement) Discrimination signal Level 1 01 h Level2 02 h Level 3 03 h Level 4 04 h . . . . . .

Moreover, the discrimination signal to be read at step S13 in FIG. 19may represent medical-field data listed in Table 5 or patient datalisted in Table 6. Based on the data, the discrimination circuit 151selects a level of compressibility.

The medical data or patient data may be recorded as data on the PC card112 in advance. The discrimination circuit 151 may read the data todetermine a level of compressibility.

TABLE 5 Discrimination signal Compressibility General surgery a Urologyb Otorhinology c Orthopedics d . . . . . .

TABLE 6 Discrimination signal Compressibility Patient a a Patient b bPatient c c Patient d d . . . . . .

(Advantage)

As mentioned above, the endoscopic imaging system 101 of this embodimentmakes it possible to change levels of compressibility automaticallyaccording to an endoscopic image for compressing image data, and thenrecord resultant data on a recording medium such as the PC card 112.Consequently, the use efficiency of a recording area on the recordingmedium can be improved, and the load imposed on an operator duringhandling can be alleviated.

Incidentally, the expansion unit 110 may be formed with a PC card.Moreover, the structure of the expansion unit 101 may be, as shown inFIG. 20, included in the CCU 107.

Moreover, this embodiment has been described by taking the TVcamera-mounted endoscope 104, which is the rigid endoscope 102 havingthe TV camera 103 mounted thereon, for instance. The embodiment is notlimited to this type of endoscope. Alternatively, a TV camera-mountedsoft endoscope, which is a soft endoscope having the TV camera mountedthereon, or an electronic endoscope having a CCD incorporated in adistal part of an insertion unit thereof will do.

Sixth Embodiment

An endoscopic imaging system of this embodiment comprises, as shown inFIG. 21, a camera head 202 to be mounted on, for example, a rigidendoscope 201 for surgery, and a camera control unit (hereinafter a CCU)203 for processing a video signal representing an object image projectedby the camera head 202. A signal cable 204 is extending from the camerahead 202. The camera head 202 is connected to the CCU 203 via aconnector 205 attached to an end of the signal cable 204. A card slot206 is formed in a lateral side of the CCU 203. A memory card 207 inwhich set data or the like that will be described later is stored can beinserted into the card slot 206.

A plurality of endoscopes can be, as shown in FIG. 22, connected to thecamera head 202. For example, a small-diameter scope 201 a employed inthe field of urology or the like, a large-diameter scope 201 b used as alaparoscope or the like, and any other endoscope having differentspecifications can be alternately mounted for use.

The CCU 203 includes, as shown in FIG. 23, a CCD drive circuit 210 fordriving a CCD 209 that is an imaging device incorporated in the camerahead 202, a pre-processing circuit 211 for pre-processing a signaloutput from the CCD 209, a wave detector 212 for detecting the waveformof an output of the pre-processing circuit 211, a light adjustmentcontrol circuit 214 for sending a control signal to the CCD drivecircuit 210 and a light source control circuit 213 for controlling anamount of light emanating from a light source, which is not shown, so asto adjust light. On the succeeding stage of the pre-processing circuit211, there are an AGC circuit 215 for controlling a gain automatically,a white balance circuit 216 for adjusting the white balance of an outputimage, a tone circuit 217 for adjusting the tone of an output image, acontour enhancement circuit 218 for enhancing the contour of an outputimage, and an encoder 219 for converting a video signal into a standardvideo signal. Thus, a video signal representing an object image isoutput to a monitor that is not shown.

Moreover, the CCU 203 is provided with a CPU 220 for controlling thelight adjustment control circuit 214, white balance circuit 216, tonecircuit 217, and contour enhancement circuit 218, a memory card driver221 connected to the memory card 207 for driving the memory card 207 ortransferring data to or from the memory card 207, and a front panel 222having an indicator for indicating setting for an operation andoperation switches arranged thereon.

Arranged on the front panel 222 are, as shown in FIG. 24, a power switch223, a connector receptor 224 into which the connector 205 of the camerahead 202 is plugged, a group of operation switches 225 for use ininstructing an operation such as white balance adjustment or contourenhancement, a luminance setting indicator 226 for indicating a setlevel of luminance for an output image, and a tone setting indicator 227for indicating a set level of tone for an output image.

Next, the operation of the endoscopic imaging system of this embodimentwill be described. In the endoscopic imaging system of this embodiment,a video signal representing an object image is photoelectricallyconverted by the CCD 209 in the camera head 202, and then input to theCCU 203. The pre-processing circuit 211, AGC circuit 215, white balancecircuit 216, tone circuit 217, contour enhancement circuit 218, andencoder 219 incorporated in the CCU 203 process the video signal. Theobject image is then displayed on the monitor that is not shown. At thistime, the wave detector 212 detects the waveform of an output of the CCD209, and outputs a wave detection signal. Based on the wave detectionsignal, the light adjustment control circuit 214 controls the CCD drivecircuit 210 and light source control circuit 213 to control lightadjustment for adjusting the brightness of an image.

With a difference in field in which an endoscope is employed, the stateof an object differs, and a way of displaying a produced image and thetone of the image differ. Adjustment values including a white balanceset value, a tone set value, a level of enhancement, and a frequencymust therefore be varied depending on an object region to be observed.Setting for an operation must thus be attained properly.

For example, for an examination or surgical procedure in the field ofurology, the camera head 202 is mounted on the small-diameter scope 201ain order to visualize an object. The object image is, as shown in FIG.25, displayed in part of the center of the monitor screen on the monitor228. For the field of surgery using a laparoscope, the camera head 202is mounted on the large-diameter scope 201b in order to visualize anobject. The object image is, as shown in FIG. 26, displayed insubstantially the whole of the monitor screen.

In this embodiment, a memory card 207 in which appropriate adjustmentvalues are stored is prepared for each object field. When the endoscopicimaging system is put to use, the camera head 202 is mounted on anassociated endoscope 201, and a memory card 207 associated with anintended field is inserted into the card slot 206. The CPU 220 reads setdata, which represent adjustment values and is stored in the memory card207, via the memory card driver 221. The CPU 220 then sends a controlsignal to each of the light adjustment control circuit 214, whitebalance circuit 216, tone circuit 217, and contour enhancement circuit218. Thus, various adjustment values are modified.

FIG. 27 shows an example of set data representing adjustment values inrelation to object fields. For the field of urology or for the fieldusing an arthroscope, the adjustment values are specified in order toattain a low speed of light adjustment, a low level of light adjustment,a bluish level of tone, and a high degree of contour enhancement.Moreover, for the field using a laparoscope, the adjustment values arespecified in order to attain a high speed of light adjustment, a highlevel of light adjustment, a reddish level of tone, and a low degree ofcontour enhancement.

For the field of urology or for the field using an arthroscope, thepicture size of an object image is small. The image tends to hunch orcause halation. The adjustment values are therefore specified in orderto attain a speed of light that is lower than the one for the fieldusing a laparoscope, and a lower level of light adjustment. A halogenlight source is often adopted for the field of urology or for the fieldusing an arthroscope, while a xenon light source is often adopted forthe field using a laparoscope. Halogen light is more reddish than xenonlight. For the field of urology or for the field using the arthroscope,tone is set to a bluish level. As for contour enhancement, since anobject in the field of urology or the field using the arthroscope isoften solely white, contour enhancement is set to a rather high level.

Since settings for operations of light adjustment control, toneadjustment and contour enhancement are thus modified, the endoscopicimaging system can be set to a state suitable for an object field bycarrying out simple handling. Endoscopic observation can therefore becarried out in an optimal operational environment all the time.

Moreover, the endoscopic imaging system of this embodiment includes analarming means for giving an alarm to a user when an incorrect memorycard inconsistent with an intended object field is inserted. Theoperation of the alarming means will be described in conjunction withFIGS. 28 and 29.

The CPU 220 in the CCU 203 reads, as described in the flowchart of FIG.28, set data representing adjustment values from the memory card 207inserted into the card slot 206 at step S21. At step S22, a picture sizefor an object image is sensed according to wave detection-relatedinformation represented by an image signal output from the CCD 209. Atstep S23, the wave detection-related information indicating the picturesize for the object image is compared with object field informationcorresponding to the set data stored in the memory card 207. It is thenjudged whether or not the picture size agrees with a picture sizespecified for an object field defined by the type of connected endoscopeor a region to be observed.

If the picture size agrees with the picture size specified for theobject field, it is judged that a correct memory card has been inserted.Control is then passed to step S24. Subsequent setting modification orthe like is carried out. By contrast, if the picture size disagreestherewith, it is judged that an incorrect memory card has been inserted.Control is passed to step S25. Alarm display is carried out. Alarmdisplay is, for example, such that an alarm having the contents shown inFIG. 29 is displayed in a screen of the monitor 228.

Owing to the alarming means, even when an incorrect memory card isinserted, a user can be informed of the fact and aware of incorrect use.A fear of establishing a set state unintended by the user can beeliminated.

Seventh Embodiment

The seventh embodiment is an example in which a memory card on whichproper adjustment values are stored is prepared for each doctor, andsettings for various operations can be modified. A memory card 207 adedicated to Dr. A shown in FIG. 30 and a memory card 207 dedicated toDr. B shown in FIG. 31 are made available. When either of the doctorsuses the endoscopic imaging apparatus, his/her own memory card isinserted into the card slot 206 of the CCU 203. Like the sixthembodiment, settings for operations of light adjustment control, toneadjustment, and contour enhancement are modified so that desiredadjustment values can be specified.

For example, assuming that Dr. A likes a bright and reddish image, setdata associated with such an image is stored on the memory card 207 a.Specifically, the brightness of the image is set to a higher level andthe tone thereof is set to a bluish level. Moreover, assuming that Dr. Blikes a dark and bluish image, set data associated with such an image isstored on the memory card 207 b. Specifically, the brightness of theimage is set to a lower level and the tone thereof is set to a bluishlevel.

In the conventional system, a setting menu screen shown in FIG. 46 isdisplayed on the monitor or the like. Settings of tone and brightnessare modified for each doctor. Handling for setting modification istherefore a rather nuisance. Moreover, an amount of data representingadjustment values, which can be stored, is limited because of thestorage capacity of a memory. This leads to a drawback that many setitems cannot be stored. By contrast, according to this embodiment,setting for an operation concerning a desired item can be modifiedreadily merely by inserting a memory card. Thus, the item can be set toan optimal value. Settings desired by a doctor can be attained byperforming simple handling. Thus, a state suitable for a user can beestablished by performing simple handling, and endoscopic observationcan be achieved under an optimal operational environment all the time.

According to the foregoing embodiment, simple handling or insertion ofan associated memory card should merely be carried out according to ause situation, that is, an object field relevant to an endoscopicexamination or a doctor in charge thereof. Thus, proper adjustmentvalues can be set in various adjusting means for carrying out lightadjustment control, tone adjustment, and contour enhancement. A properoperational environment can be established readily.

Incidentally, the endoscopic imaging system of this embodiment is notlimited to an endoscope system for surgery in which a camera head ismounted on a rigid endoscope as described in conjunction with theprevious embodiments. The endoscopic imaging system can also be adaptedto an endoscope system for internal medicine in which a camera head ismounted on a soft endoscope or to an electronic endoscope having animaging device incorporated therein.

Moreover, the memory card is not limited to a PC card having a memoryincorporated therein. A card to which a compact memory card such as asmart medium can be detachably attached, or a card having a compact harddisk incorporated therein can also be adapted to the aforesaidembodiments.

Moreover, the card slot to which the memory card is connected is notlimited to a structure formed in a lateral side of a CCU. Alternatively,a structure separated from the CCU and detachably attached to the CCUmay be adopted.

Eighth Embodiment

As shown in FIG. 32, an endoscopic imaging system 301 of this embodimentcomprises a camera head 302 having an imaging means incorporatedtherein, a scope 303 connected to the camera head 302, a light sourceapparatus 304 for supplying illumination light to the scope 303, acamera control unit (hereinafter a CCU) for processing a signal sentfrom the imaging means in the camera head 302, and a TV monitor 306 fordisplaying a standard video signal processed by the CCU 305. The scope303 is a rigid endoscope such as a laparoscope used for, for example, asurgical procedure in the field of surgery.

When the endoscope imaging system 301 is put to use, a light guide 308of the scope 303 is, as shown in FIG. 32, linked to the light sourceapparatus 304. Illumination light emanating from a lamp in the lightsource apparatus 304 passes through a diaphragm that is not shown, isconverged by a lens, and falls on an opposed end surface of the lightguide 308. The illumination light is transmitted to the scope 303 overthe light guide 308, propagated through the scope, and emitted forwardthrough the distal end of the scope 303. An object such as a patient'sbody cavity is then illuminated. An image represented by light reflectedfrom the illuminated object is formed by the scope 303. The object imageis projected by the imaging means in the camera head 302 through thescope 303.

A CCD 307 serving as the imaging means is located on the focal plane ofan imaging lens in the camera head 302. The object image is formed onthe image plane of the CCD 307 and converted photoelectrically. The CCD307 is connected to the CCU 305 over a camera cable 309 in which a CCDdriving signal transmission line and a CCD output signal transmissionline are inserted. An output signal of the CCD 307 is sent to the CCU305 and subjected to various kinds of signal processing. A video signaloutput from the CCU 305 is sent to the TV monitor 306. A view image ofthe object is then displayed on the TV monitor 306.

The CCU 305 is provided with a CCD driver 310. The CCD driver 310supplies a CCD driving signal to the CCD 307 over the CCD driving signaltransmission line in the camera cable 309. A signal charge accumulatedin the CCD 307 is then read. Moreover, the CCU 305 is provided with apreamplifier 311 and a pre-processing circuit 312. A CCD output signalread by the CCD 307 is transmitted to the CCU 305 over the CCD outputsignal transmission line in the camera cable 309. After the CCD outputsignal is amplified by the preamplifier 311 in the CCU 305 in order tocompensate for a loss occurring during cable transmission, it is inputto the pre-processing circuit 312.

On a succeeding stage of the pre-processing circuit 312, there are anA/D converter 313 and a Y/C separation circuit 314. A CCD output signalinput to the pre-processing circuit 312 is pre-processed by performingcorrelation double sampling (CDS) and sample-and-hold (S/H). Theresultant signal is then input to the A/D converter 313 and convertedinto a digital signal. The digital signal is then input to the Y/Cseparation circuit 314.

On a succeeding stage of the Y/C separation circuit 314, there are anRGB matrix circuit 315 and a white balance/black balance adjustmentcircuit 316. A digital signal input to the Y/C separation circuit 314 isrecomposed in conformity with the line sequential system. Digitalsignals Y, CR, and CB to be propagated through three channels areseparated from one another, and input to the RGB matrix circuit 315. Thedigital signals are then converted into an RGB digital signal.Thereafter, the white balance/black balance adjustment circuit 316adjusts the white balance and black balance of the signal.

On a succeeding stage of the white balance/black balance adjustmentcircuit 316, there are a digital video processing circuit 317, a D/Aconverter 318, and a post-processing circuit 319. An RGB digital signalwhose balance has been adjusted is digitally processed throughenhancement, gamma correction, and character convolution performed bythe digital video processing circuit 317. Thereafter, the signal isconverted into an analog signal by the D/A converter 318, and then inputto the post-processing circuit 319. The analog signal that is input tothe post-processing circuit 319 is converted into a standard videosignal and output to the TV monitor 306.

On the succeeding stage of the digital video processing circuit 317,there are a memory 320, a JPEG compression circuit 321, and a PC carddriver 322. A PC card slot 323 is connected to the PC card driver 322. Adigital signal having undergone various kinds of signal processing isstored in the memory 320. A PC card 324 having a memory incorporatedtherein is mounted in the PC card slot 323. After a digital image signalread from the memory 320 is compressed by the JPEG compression circuit321, it is recorded on the PC card 324 via a PC card driver 322.

Furthermore, a CPU 325 responsible for various kinds of controlincluding control of recording of image on the PC card 324, a connectionsensing means 326 for sensing the connected state of the PC card 324,and a character generator 327 for outputting medium information thatincludes the recorded situation of image data on the PC card 324 andappears as a display screen are included in the CCU 305. A releaseswitch 329 used to give a handling instruction (release instruction) forimage recording is formed on the front panel 328 of the CCU 305.

As shown in FIG. 33, a power switch 330, a connector receptor 331 towhich the camera head 302 is plugged, the PC card slot 323, andoperation switches 332 including the release switch 329 are arranged onthe front panel 328 of the CCU 305.

Referring to FIGS. 32, 34 and 35, the configuration and operation of animage recording unit for compressing and recording data of a projectedimage will be described. An image signal visualized and processed by thecamera head 302 via the scope 303 is output to the TV monitor 306,displayed as an image on the TV monitor and then stored in the memory320.

When the release switch 329 is pressed in order to record an endoscopicimage, the CPU 325 sends a release signal to the memory 320. Image datarepresenting a still image is read from the memory 320. The read imagedata is compressed by the JPEG compression circuit 321. The resultantdata is sent to and recorded on the PC card 324 mounted in the PC cardslot 323 via the PC card driver 322.

The JPEG compression circuit 321 is designed to carry out unilateralencoding based on the discrete cosine transform (DCT). The JPEGcompression circuit 321 consists of a DCT circuit 335, a quantizationcircuit 336, a quantization table 337, an entropy encoder 338 and aHuffman coding table 339. Compression of image data is carried out asdescribed below.

Assume that the precision or resolution of input image data is eightbits. The input image data is divided into blocks each composed of 8 by8 pixels. The DCT circuit 335 performs two-dimensional DCT on a blockcomposed of 8 by 8 pixels. Thereafter, the quantization circuit 336linearly quantizes a DCT coefficient using the quantization table 337that lists a set of discrete values in steps whose size is differentfrom coefficient to coefficient. By modifying the values listed in thequantization table 337, image quality and a magnitude of encoding can becontrolled. The entropy encoder 338 uses the Huffman coding table 339 toencode image data as entropy. Specifically, a DC component and ACcomponents of a quantized DCT coefficient are encoded independently.Resultant code data is output as image data. Herein, the Huffman codingis adopted as the entropy encoding.

During image recording, the CPU 325 reads information of a storagecapacity for image data on the PC card 324 and information of theconnected state of the PC card 324 sensed by the connection sensingmeans 326. Information of the recorded situation of the image data onthe medium is output. The connected state of the PC card 324 is sensedby checking a high-level or low-level signal that is output from theconnection sensing means 326 according to whether or not the PC card 324is inserted in the PC card slot 323.

The CPU 325 includes a remaining capacity sensing means for sensing aremaining storage capacity on the PC card 324, and an arithmeticcalculation means for calculating the number of recordable imagesaccording to the sensed remaining storage capacity. Medium informationincluding the number of recordable images, which is output from the CPU325, is output as character information from the character generator327. The character information is superimposed on an image in a screenon the TV monitor 306.

FIG. 36 shows an example of a display screen on the TV monitor 306.Medium information 342 concerning the connected state of the PC card 324and the recorded state of image data on the PC card 324 is displayedtogether with an endoscopic image 341 projected by the camera head 302at, for example, a right lower corner of the screen on the TV monitor306. “PC card connected” indicating that the PC card 324 has beenconnected normally, and “The number of remaining images is 3” indicatingthe number of images recordable on the PC card 324 are displayed.

When an endoscopic image is thus recorded using a PC card, a still imagewhose quality has little deteriorated can be recorded and stored at lowcost. Moreover, when the image is recorded, medium information such asthe recorded situation of image data on the PC card can be superimposedon a view image on a monitor. A user can therefore recognize theconnected state of the PC card and the number of remaining recordableimages readily.

When digital image data is compressed and recorded on a medium such as aPC card, the number of remaining recordable images varies depending on alevel of compressibility of data or a storage capacity on a medium. Itis therefore hard for a user to grasp the recorded situation of imagedata. According to this embodiment, medium information can be checkedaccurately. It can be prevented that recording a necessary image failsbecause of imperfect connection of the PC card or an insufficientstorage capacity.

Ninth Embodiment

The ninth embodiment is an example of a configuration where mediuminformation is displayed on a liquid crystal display (hereinafter anLCD) on the front panel of a CCU.

As shown in FIG. 37, the CCU 305 has, in addition with the components ofthe eighth embodiment shown in FIG. 32, an LCD 345 formed on the frontpanel thereof. The CCU 305 also has an LCD driver 346 for driving theLCD 345 therein. The LCD driver 346 is connected to the CPU 325 andcharacter generator 327. Character information of medium informationgenerated by the character generator 327 is displayed on the LCD 345.

The components of this embodiment other than the components relevant todisplay of medium information and the operation thereof are identical tothose of the eighth embodiment. The description will be omitted.

During image recording, the CPU 325 reads information of a storagecapacity for image data on the PC card 324 and information of theconnected state of the PC card sensed by the connection sensing means326 in the same manner as that if the eighth embodiment. The number ofrecordable images or the like is then calculated. The information of therecorded situation of image data on the medium is then output. Mediuminformation such as the number of recordable images output from thecharacter generator 327 is output as character information from thecharacter generator 327 to the LCD driver 346. The medium information isdisplayed on the LCD 345 on the front panel of the CCU 305.

FIG. 38 shows an example of an information display on the LCD 345.Medium information identical to the one in the eighth embodiment, thatis, medium information 347 concerning the connected state of the PC cardand the recorded state of image data on the PC card 324 is displayed onthe LCD 345. “PC card connected” indicating that the PC card 324 hasbeen connected normally, and “The number of remaining images is 3”indicating that the number of remaining images recordable on the PC card324 are displayed.

Medium information such as the recorded situation of image data on a PCcard is displayed on the front panel of a CCU or the like separatelyfrom a view image on a monitor. A user can therefore recognize theconnected state of the PC card and the number of remaining recordableimages as readily as he/she can in the eighth embodiment. Moreover,according to the ninth embodiment, an endoscopic image alone isdisplayed on the monitor. The display of medium information will nothinder viewing of an endoscopic image. The user can recognize the stateof a medium any time without hampering observation or surgery.

Tenth Embodiment

The tenth embodiment is an example of a configuration including analarming means for displaying medium information only when it is neededand for giving an alarm to a user.

The CCU 305 has, in addition to the components of the eighth embodimentshown in FIG. 32, as shown in FIG. 39, a loudspeaker 351 for alarming.The loudspeaker 351 is connected to a loudspeaker driver 352 forconverting a notification signal output from the CPU 325 into a voicesignal. The components of the tenth embodiment other than the componentsrelevant to the alarming means are identical to those of the eighthembodiment. The description of the components will be omitted.

According to the tenth embodiment, when needed, or specifically, whenthe PC card 324 is not mounted normally or the number of remainingimages recordable on the PC card 324 becomes zero, medium information isdisplayed or superimposed on an image in a screen on the TV monitor 306.Thus, a user' attention is called.

The CPU 325 calculates the number of recordable images using informationof a storage capacity for image data on the PC card 324, and informationof the connected state of the PC card 324 sensed by the connectionsensing means 326. When it is necessary to inform a user of mediuminformation, for example, when image recording cannot be achievednormally, the medium information is output to the character generator327. At the same time, a notification signal is output to theloudspeaker driver 352. The medium information sent from the CPU 325 isoutput as character information from the character generator 327 andsuperimposed on an image in a screen on the TV monitor 306. In addition,an alarming voice saying, for example, “Replace the PC card with a newone,” is uttered by the loudspeaker 351.

FIG. 40 shows an example of a display screen on the TV monitor 306.Medium information 353 concerning the connected state of the PC card 324and the recorded state of image data on the PC card 324 is displayedtogether with an endoscopic image 341, which is projected by the camerahead 302, at, for example, the right lower corner of a screen on the TVmonitor 306 only when it is needed. In this example, when the number ofimages recordable on the PC card 324 becomes zero, a message saying “Thenumber of remaining images is zero. Replace the PC card with another.”is displayed in order to prompt a user to replace a medium with another.

As mentioned above, only when medium information such as the recordedsituation of image data on the PC card is needed, it is superimposed ona view image on the monitor or a voice is uttered. A user can thereforerecognize the connected state of the PC card or the recorded situationof image data readily at a right time without discontinuing observationor hampering surgery. Thus, a failure in recording an image, the loss ofa necessary image due to overwriting of a recorded image, or any othermistake can be prevented from being made during image recording.

According to a variant concerning notification of medium information,before the number of recordable images becomes zero, when the number ofrecordable images becomes equal to or smaller than a given value (forexample, 2), a display may be provided in order to inform a user of thefact.

Eleventh Embodiment

The eleventh embodiment is an example of a configuration including areproducing means for reproducing image data of a still image recordedon a PC card.

The CCU 305 has, in addition to the components of the eighth embodimentshown in FIG. 32, a JPEG stretch circuit 335 connected in parallel tothe JPEG compression circuit 321 between the PC card driver 322 andmemory 320. The JPEG stretch circuit 355 processes data by reversing theprocedure followed by the JPEG compression circuit 321. In other words,the JPEG stretch circuit 355 stretches image data that has been encodedto be compressed, and thus restores it to original image data. Thecomponents other than the components relevant to the reproducing meansare identical to those of the eighth embodiment. The description of thecomponents will be omitted.

For reproducing image data of a still image recorded on the PC card 324,image data is read from the PC card 324 via the PC card driver 323 inresponse to an instruction sent from the CPU 325. The image data isstretched by the JPEG stretch circuit 355, and then stored in the memory320. The stretched image data is read from the memory 320, and convertedinto a standard video signal by the D/A converter 318 andpost-processing circuit 319. The resultant image data is output to anddisplayed on the TV monitor 306.

FIG. 42 shows an example of a display screen on the TV monitor 306. Astill image 356 recorded on the PC card 324 is reproduced and displayedin a screen on the TV monitor 306.

Since a still image recorded on a PC card can thus be displayed, a usercan check if the recorded image is necessary. Consequently, unnecessaryimages can be identified and deleted. A larger number of necessaryimages can be recorded on the PC card. Moreover, a PC card must bereplaced with another at a minimum frequency during an endoscopicexamination. The labor of replacing a medium with another can beminimized, and the cost required for the running of a medium can bereduced.

Twelfth Embodiment

The twelfth embodiment is an example of a configuration including an LEDfor displaying a releasing frequency on the front panel of a CCU.

The CCU 305 has, in addition to the components of the eighth embodimentshown in FIG. 32, as shown in FIG. 43, an LED 361 for displayingnumerals, such as, a seven-segment display formed on the front panelthereof. Moreover, a font generator 362 for driving the LED 361 fordisplay is incorporated in the CCU 305. The font generator 362 isconnected to the CPU 325. Based on information concerning releaseperformed during image recording, which is output from the CPU 325,information of a releasing frequency is indicated with numerals on theLED 361. The components of the twelfth embodiment other than thecomponents relevant to display of the releasing frequency are identicalto those of the eighth embodiment. The description of the componentswill be omitted.

When the release switch 329 is pressed in order to record an endoscopicimage, the CPU 325 sends a release signal to the memory 320. Image dataof a still image is then read from the memory 320. The read image datais compressed by the JPEG compression circuit 321, and sent to andrecorded on the PC card 324 mounted in the PC card slot 323 via the PCcard driver 322. At this time, the CPU 325 sends release information tothe font generator 362, and numerals indicating a releasing frequencyare displayed on the LED 361. The releasing frequency is incremented byone with every release.

As mentioned above, a display means for displaying medium informationconcerning the number of images that are represented by image data andrecordable on the PC card is formed on the front panel of a CCU or thelike. A user can therefore readily recognize the recorded situation ofimage data such as the number of remaining images recordable on the PCcard.

The adaptation of the endoscopic imaging system of this embodiment isnot limited to an endoscope system for surgery in which a camera head ismounted on a rigid endoscope as described in conjunction with theprevious embodiments. The endoscopic imaging system can also be adaptedto an endoscope system for internal medicine in which a camera head ismounted on a soft endoscope or an electronic endoscope having an imagingdevice incorporated therein.

Moreover, the PC card is not limited to a card having a memoryincorporated therein. Even a card to which a compact memory card such asa smart medium can be detachably attached or a card having a compacthard disk incorporated therein can be adapted to the aforesaidembodiments.

Moreover, the PC card slot to which a PC card is connected is notlimited to a structure formed on the front panel of a CCU.Alternatively, a structure provided separately from the CCU anddetachably attached thereto will do.

According to the present invention, it is apparent that a wide range ofdifferent embodiments can be constructed without a departure from thespirit and scope of the present invention. This invention is limited tothe appended embodiments but not restricted to any specific embodiments.

What is claimed is:
 1. An endoscope imaging system comprising: animaging device for projecting an object image of an object in a bodycavity; and a signal processing unit for processing an image signal sentfrom said imaging device, wherein said signal processing unit comprisesa signal processing circuit for processing said image signal sent fromsaid imaging device to produce an image signal; an image signal outputterminal for outputting said image signal produced by said signalprocessing circuit to a display unit; a memory which can temporarilystore said image signal produced by said signal processing circuit; a PCcard slot into which a PC card for recording therein said image signalstored in said memory, with a connector for detachably connectingthereto said PC card; a release switch operative to send out said imagesignal from said memory in order to record said image signal stored insaid memory in said PC card detachably connected to said connector; anda compression circuit for digitally compressing said image signal sentout from said memory in response to the operation of said release switchand sending said digitally compressed signal image signal to be sent tosaid PC card detachably connected to said PC card slot via saidconnector.
 2. An endoscopic imaging system according to claim 1, whereinsaid PC card slot of said signal processing unit has an anti-liquidinvasion structure.
 3. An endoscopic imaging system according to claim1, wherein said PC card slot of said signal processing unit has a shieldfor providing shielding against electromagnetic waves.
 4. An endoscopicimaging system according to claim 1, wherein said PC card slot of saidsignal processing unit has an anti-liquid invasion structure and ashield for providing shielding against electromagnetic waves.
 5. Anendoscopic imaging system according to claim 2, wherein said anti-liquidinvasion structure is formed as a projection on a surface of the signalprocessing unit having a width larger than said PC card slot on an upperperiphery of an opening of said PC card slot.
 6. An endoscopic imagingsystem according to claim 2, wherein said anti-liquid invasion structureis formed as a lid member over an opening of said expansion slot so thatsaid lid member can be opened or closed freely.
 7. An endoscopic imagingsystem according to claim 2, wherein said anti-liquid invasion structureis formed by an inner lower surface of said expansion slot near anopening thereof, the inner lower surface being sloped so as to inclinetoward the opening.
 8. An endoscopic imaging system according to claim4, wherein said anti-liquid invasion structure and said shield comprise:a lid member made of a conducting material over an opening of said PCcard slot so that said lid member can be opened or closed freely; anelectrically conductive contact member formed on the perimeter of theopening of said PC card slot for conducting electricity to a housingshield portion of said signal processing unit; and a constrainingelement for causing said lid member to close and meet said contactmember when said PC card unit is not inserted into said PC card slot. 9.An endoscopic imaging system according to claim 8, wherein a back endportion of said PC card which remains exposed when said PC card isinserted into said PC card slot is coated with a conductive materialsuch that when said PC card is inserted inside said PC card slot, saidconductive material and said contact member meet; and the back endportion of said PC card blocks the opening of said PC card slot whensaid PC card is inserted therein.
 10. An endoscopic imaging systemaccording to claim 1, wherein said signal processing circuit processessaid image signal sent from said imaging device to produce a digitalimage signal and an analog image signal.
 11. An endoscopic imagingsystem according to claim 10, wherein said image signal output terminaloutputs said analog image signal produced by said signal processingcircuit to the display unit.
 12. An endoscopic system according to claim10, wherein said compression circuit digitally compresses the digitalimage signal produced by said signal processing circuit.
 13. Anendoscopic imaging system according to claim 1, wherein said compressioncircuit digitally compresses said digital image signal read from saidmemory which temporarily stores the digital image signal produced bysaid signal processing circuit.
 14. An endoscopic imaging systemaccording to claim 13, wherein said compression circuit reads saiddigital image signal corresponding to a still image from said memory.